扁穗牛鞭草人工草地中空心莲子草杂草防除效果研究

利用水花生净除莠剂可有效地防除扁穗牛鞭草人工草地中的杂草空心莲子草,平均株防效达26.7%～99.8%,并且在较高防效下药剂对扁穗牛鞭草较为安全。在空心莲子草杂草生长盛期,14%的水花生净乳油以浓度为675ml/hm2～900ml/hm2、各处理对水600ml的防除效果最佳,可达到100%。综合考虑,以525ml/hm2～675ml/hm2的浓度为宜。     

两种除草剂混配在燕麦田的应用效果研究

为了筛选安全高效的燕麦田除草剂,选用50%二氯喹啉酸可湿性粉剂和40%二甲·辛酰溴乳油两种除草剂,以不同浓度混配后施于燕麦田,研究其对燕麦田杂草的防除效果以及对燕麦安全性和产量的影响。结果表明:不同处理对杂草的防效差异显著(P0.05),混配处理的防效平均在75%,高于各单剂处理。药后15d40%二甲·辛酰溴乳油和50%二氯喹啉酸可湿性粉剂混配处理(1 400mL/hm2+225g/hm2)的株防效最高,为86.23%。药后30d的防效同样以40%二甲·辛酰溴乳油和50%二氯喹啉酸可湿性粉剂混配处理(1 400mL/hm2+225g/hm2)的最高,其鲜重防效可达到98.81%。40%二甲·辛酰溴乳油和50%二氯喹啉酸可湿性粉剂混配处理(1 400mL/hm2+225g/hm2)还能显著提高燕麦干草产量,与对照相比可增产16.4%,达到10 404kg/hm2。籽粒产量以40%二甲·辛酰溴乳油和50%二氯喹啉酸可湿性粉剂(700mL/hm2+225g/hm2)处理最高,为2 564.27kg/hm2,相比对照增产37.4%。     

螟纹杀克防治水稻二化螟和稻纵卷叶螟试验

螟纹杀克1050～1350g/hm2对水稻二化螟和稻纵卷叶螟有很好的防治效果,药后7天对二化螟及稻纵卷叶螟的防效分别达93.7%以上和95.0%以上,药后20天的保苗率及保叶效果分别达89.0%以上和84.7%以上,可使水稻增产20.0%～21.8%.     

41%草甘膦异丙胺盐水剂防除茶园杂草试验

试验表明 ,41%草甘膦异丙胺盐水剂防除茶园杂草 ,无药害 ,茶树生长正常 ,无论是禾本科杂草 ,还是双子叶、阔叶杂草均有很好的防除效果。总体株防效 (药后 35天 )达到 85 2 3%以上 ,鲜重防效 (药后 35天 )达97 5 9%以上     

SL-160防除草坪杂草应用技术研究

用25%SL-160颗粒剂对马尼拉草坪进行了茎叶处理和土壤处理.结果表明,150～300g/hm2茎叶处理可有效地防除香附子、天胡荽、牛繁缕、大巢菜等草坪杂草,药后60d对香附子的校正防效为80.59%～100%,对天胡荽的校正防效为71.58%～100%,施药时加入885助剂225ml/hm2可适当提高药后早期的防效,但对最终防效影响不明显;150～300g/hm2作土壤处理,对杂草的出苗影响不大,但对出苗后杂草的生长却有很强的作用,药后65d对马唐、牛筋草、狗尾草、香附子的鲜重防效分别为100%、78.40%～99.5%、95.60%～99.70%、87.20%～99.60%.     

SL-160对马尼拉草坪杂草的防除效果

秀百宫 (shibagen) 2 5 %水分散粒剂 ,通用名flazasulfuron ,啶嘧磺降代号SL 16 0。用SL 16 0马尼拉草坪上进行草坪杂草防除试验。结果表明 :各处理的SL 16 0对阔叶、莎草科杂草的防效均达10 0 % ;对禾本科杂草而言 ,高剂量SL 16 0 (45 0 g/hm2 )对杂草防效较好 ,对稗草及千金子防效达 10 0 % ,对 5叶期后的马唐、牛筋草抑制作用最强。SL 16 0对马尼拉草坪生长和草坪质量没有影响 ,可大面积推广应用。     

甲咪唑烟酸与烯草酮混配对紫花苜蓿生长影响及除草效果研究

为明确甲咪唑烟酸与烯草酮混配应用于紫花苜蓿(Medicago sativa)田的可行性,2019年在田间测定甲咪唑烟酸与烯草酮不同混配的除草效果及对紫花苜蓿生长的影响。结果表明：药后14 d,混配处理对紫花苜蓿株高、分枝数、地上部鲜重均有抑制,但抑制率低于甲咪唑烟酸处理;药后28 d,混配处理对株高的抑制率降低,而分枝数、地上部鲜重、产量显著高于对照组和两种单剂处理(P<0.05),对品质无影响;与甲咪唑烟酸、烯草酮单用相比,混配处理显著提高马唐、旱稗等禾本科杂草的防效(P<0.05),杂草总防效90%以上,增产率13%以上,增产效果显著。综上所述,甲咪唑烟酸(86.4～100.8 g·hm^-2)与烯草酮(54.0～108.0 g·hm^-2)混配对紫花苜蓿的抑制作用在后期得到缓解,有效防除杂草,提高紫花苜蓿产量,具有良好的应用前景和价值。     

甘孜州高寒地区多年生禾草混播人工草地杂草防除研究

为了筛选出防除混播多年生人工草地阔叶杂草的适宜施药剂量,在甘孜县昌台开展了阔极(苯-唑-2甲钠)除杂试验。结果表明:900、1200、1500g/hm2阔极对阔叶杂草株总防效分别达到75.9%、87.1%、93.8%,鲜重总防效分别达到76.8%、85.0%、90.5%。当阔极用量达到1500g/hm2,混播多年生人工草地幼苗产生较大的药害反应。综合考虑施药安全性与成本最小化原则,确定阔极1200g/hm2为防除甘孜高寒地区多年生禾草人工草地阔叶杂草适宜使用剂量。     

几种选择性除草剂防除草坪双子叶杂草效果的研究

在1997 ～1998 年两年间,应用好事达、百草敌、使它隆、2 ,4 - D 丁酯四种选择性杂草防除剂对四川农业大学校园草坪杂草进行防除试验。结果表明:防除草坪中的双子叶杂草用72 % 的2,4 - D 丁酯2500ml/hm2 + 使它隆1000ml/hm2 ,株防效为90-3 % ,种防效为74 % ,效果最好,经方差检验,与其它几种处理的差异达到了显著或极显著的水平。     

几种新型农药防治茶尺蠖田间试验

以30%唑虫酰胺、白僵菌、苏云金杆菌、茚虫威四种农药为材料开展茶尺蠖田间防效试验。结果表明:四种农药药后第1天苏云金杆菌防效最低,防效70.59%,其它三种在81.43%~88.74%,茚虫威防效最好,其次是唑虫酰胺。用药后14天四种农药防效都达95%以上,苏云金杆菌95.55%,其它农药都达100%,苏云金杆菌防效与其它农药防效有显著差异。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein